Custom fitting of golf clubs can substantially improve a golfer's performance, and accordingly, is quite popular, particularly when an established golfer is upgrading or replacing a set of golf clubs. A considerable number of variables must be considered when golf clubs are being custom fitted, see "Golf Club Design, Fitting, Alteration and Repair" by Ralph D. Maltby. Loft, lie, and, for wood golf clubs, face angle are among the variables considered.
In a wood golf club, which is defined by the United States Golf Association (USGA) as having a head relatively broad from face to back and usually is made of wood, plastic or a light metal, loft is the angle of the face on its centerline to a line perpendicular to the sole line measured in degrees. Loft is determined at a point one half the distance of the face height. Lie is the angle of the center line of the shaft with the ground line tangent to the sole at the center line of the face. And the angle of the face of a wood golf club to the grounded sole line with the shaft hole perpendicular to the line of flight is the face angle.
The lie and face angle of a wood golf club having a wood head may be determined and adjusted by changing the drill angle on the hosel or neck of the wood head and the turning the neck in alignment with the drilled hole. Loft is normally determined by the shape of the face of the head and its orientation relative to the sole. However, the effective loft of a wood golf club is affected by its face angle, and hence, all three characteristics are to some extent interrelated.
As suggested by the USGA definition, heads for wood golf clubs are now commonly made of molded plastic materials or of cast metals. Unfortunately, when nonwood materials are used to form a wood golf club head, drilling and turning operations to determine the face angle and possibly the lie are impractical. It is also not possible to bend the hosel or neck of the club head because typically such heads are of a hollow construction such that the neck would be weakened and even if the neck could be bent, the club would not "look right" and would not be acceptable to golfers. While it is possible to form a plurality of nonwood golf club heads having varying lies and face angles, the mold costs and inventory problems are prohibitive.
It is thus apparent that the need exists for a wood golf club head which is formed of nonwood material which can have its face angle and/or lie adjusted without changing the angle of the hosel or neck for fitting a golf club incorporating the head to an individual golfer.